textquery

Process text files in relational way, using SQL.

Features

• support projection, filter, group by order by, limit-offset
• support join, set op, subquery like in/not in, exist, not exist, = etc
• support time functions, string functions

Architecture

- Parser 
 - Plan
  - Relational Operator
    - DataSource

Demo

Basic Example

a.txt has content below

China is in Asia
USA  is in America
Germany  is in Euro
France  is in Euro

can be queryed using follow bash cmd

textquery "select c1 from a.txt where c4 = 'Euro'"

the output is

Germany
France

Group By Example

a.txt has content below

China | Asia
USA | America
Germany | Euro
France | Euro

can be queryed using follow bash cmd

textquery "select c2, ' ', group_concat(c1, ',') from a.txt group by c2"

the output is

China Asia
USA America
Euro Germany,France

Subquery Example

blacklist.txt：

Tom
Jerry
Smith
Alice
Bob

user.txt：

Tommy
Bob
Jack

Want to know good guys in user.txt? just type

textquery "select * from user.txt where c1 not in (select * from blacklist.txt)"

you will get

Tommy
Jack

Join Example

a.txt has content below

China is in Asia
USA  is in America
Germany  is in Euro
France  is in Euro

b.txt has content below

Asia | Sunny
Ameria  | Cloudy
Euro |  Rainy

can be queryed using follow bash cmd

textquery "select t1.c1, ',' t2.c2 from a.txt t1, b.txt t2 where t1.c4 = t2.c1"

this will generate content below

China,Sunny
USA,Cloudy
Germany,Rainy
France,Rainy